Say it is isn’t so. But according to a meta-analysis performed by researchers at the University of Tokyo, hairlessness is connected to heart disease.

What Did They Find?

Among 37,000 men taken from 6 studies out of a possible 850, baldness “increased” the risk of heart disease.

How Was the Study Done?

The researchers looked at most studies of the subject, dumped most, and then reorganized and re-analyzed the data according to their own prescriptions and beliefs.

How Accurate is That?

Depends on the data and the analyzers. Many epidemiologists love such meta-analyses. This was done in part using the Cochrane Library, a vast international data base. Such meta-analyses increase the “power” of statistical study to show real results. However, others think such studies put together apples and plums and then provide results for apples.

Not all studies are equally reliable – even if you put them all together.

What Else Did The Researchers Show?

The worse the baldness, the worse the risk. And the risk only exist for men who grew bald from the crown, not the front (“vertex risk”). These are the kind of results that seem to increase biologists’ belief in the results, as they follow linear models of disease increase.

Not all biological behavior is linear. What we have here is another “risk factor” for heart disease. Already there are hundreds.

What Is a Risk Factor?

A statistical correlate that hopefully means something in the natural world. Cholesterol is perhaps the most famous risk factor for heart disease, but the list is very long. If each of them were naively added together, many of us would possess a 5000% chance of getting heart disease.

Getting a hair transplant won’t decrease your risk of heart disease – though probably some dermatologists and plastic surgeons will be advertising such before long.

Correlation is not causation. Even if 85% of Americans die in bed, that does not mean beds kill people. If anything, bed use seems to increase populations.

So What Do Risk Factors Measure?

Generally some biological correlate of risk. Cholesterol presumably works through increasing atherosclerosis, or changing inflammation, but that argument is ongoing.

How Would Baldness Be Bad for the Heart?

The standard research answer is given by the authors – “the association between male pattern baldness and coronary heart disease deserves further investigation.”

That’s a polite way of saying nobody knows.

What you do know – the body continually regenerates itself to survive, constantly rejiggering its information formats. As it does we become bigger or smaller, taller or thinner, remain hairy or lose more hair. Since we are not immortal, aging seems to muck up the regenerative process.

Loss of hair may related to genes that remake arteries, to general levels of inflammation, or perhaps just the enduring sadness of otherwise vigorous males losing their reproductive allure to the opposite sex. It may also be related to the chemicals in the air or water, antidepressant or anti-seizure drug use, antibiotic levels in meat, pollution, or the economic and family stress of our times that literally do cause hair to fall out.

Chances are it’s related – “associated” – with a lot of things. That’s why researchers get notably cagey when explaining what their results actually mean.

Do We Take Risk Factors Too Seriously?

Absolutely. Drug companies made such a pile with statins that they started believing their own advertising – that changing risk factors would change health. They had already convinced the FDA.

So they spent billions on drugs increasing HDLs – high density lipoproteins – the “good” cholesterol. Those drugs worked. HDL levels went up.

As did cardiac deaths.

It turned out that statins worked very well for some reasons other than originally stated – that is, through lowering cholesterol. They did things to arterial membranes that were very helpful.

Once again, correlation is not causality.

Bottom Line:

Be skeptical.

Recognize that not just the media, the public, but many clinicians and researchers do not understand the intricacies of the normative, Gaussian statistics they routinely use to tell if studies are “significant” or not.

Risk factors are just that – risk correlates. Some have a lot of meaning, others close to none.

End points matter. It’s better for most men to have a full head of hair.